Improvement in lifting-jacks



UNITED STATES PATENT QFFIGE;

WILLIAM Z. BLACK, OF ROANN, INDIANA.

IMPROVEMENT IN LlFTlNG-JACKS.

Specification forming part of Letters Patent No. 198,138, dated July 17, 1877 application filed February 17, 1877.

To all whom it may concern Be it known that 1, WILLIAM Z. BLACK, of

Roann, in the county of Wabash and State of had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification.

The same letters and figures of reference are used to indicate the corresponding parts.

After describing the invention, its nature and extent will be shown in the claims.

My invention is an improvement in liftingjacks which are principally used in raising carriages from the ground.

It consists of a lever with a convex-shaped shoulder, sliding ratchet-bar, and a dog engaging with the ratchet-bar.

Figure 1 is a side view of my invention. Fig. 2 is a vertical sectional view, and Fig. 3 is a detachedview of the top of the ratchetbar.

A is the base, and B the upright or standard, into a central slot of which the ratchetbar 0 plays in a vertical direction. D is a lever, pivoted at d to a shoulder of the base A. One end of the parallel bracing-plates H is pivoted to the standard B at the point b, and the other end to the shoulder at d.

The engaging-dog G is composed of two parallel plates, one end of which is pivoted at d of the convex-shaped end of the lever D. The other end of the-dog moves in the notches E of the ratchet-bar O.

F is a guard which confines the upper end I dation.

Having now fully described my invention, what I claim, and desire to secure by Letters Patent, is-

1. In a lifting-jack, the sliding ratchet-bar 2. The lever D, the bracing-plates H, and' the base A and standard B, in combination with the parallel engaging-dogs G, one end of Y which is confined by the protecting-bar F to the ratchets E, and the sliding ratchet-bar 0, moving in a vertical central slot of the standard B, substantially as described, and for the purposes set forth.

In testimony that I claim the foregoing I have hereunto set my hand this 5th day of February, 1877.

WILLIAM Z. BLACK.

Witnesses A. W. HOFFMAN, LEVI PATTERSON. 

